1. Field of the Disclosure
The present disclosure relates to a liquid crystal display (LCD) device, and more particularly, to an array substrate for a fringe field switching mode LCD device in which multiple domains are formed without lowering transmissivity to prevent occurrence of a color shift phenomenon, thereby improving display quality.
2. Discussion of the Related Art
In general, a liquid crystal display (LCD) device is driven using optical anisotropic and polarization properties of liquid crystal. The liquid crystal has a slender and long structure and thus has directionality in a molecular arrangement thereof. A direction of the molecular arrangement may be controlled by artificially applying an electric field to the liquid crystal.
When the direction of the molecular arrangement of the liquid crystal is arbitrarily controlled, the molecular arrangement of the liquid crystal changes and light is refracted in the direction of the molecular arrangement of the liquid crystal due to the optical anisotropic properties of the liquid crystal, thereby displaying image information.
Recently, much attention has been paid to an active matrix LCD (AM-LCD) in which a thin film transistor (TFT) and a pixel electrode connected to the TFT are arranged in a matrix (hereinafter abbreviated as ‘LCD’), since the AM-LCD has high resolution and capability of displaying moving pictures.
An LCD includes a color filter substrate on which a common electrode is formed, an array substrate on which a pixel electrode is formed, and liquid crystal between the two substrates. The LCD has high transmissivity and aperture ratio, since the liquid crystal is driven using an electric field that is vertically applied to the common electrode and the pixel electrode.
However, when the liquid crystal is driven using the vertically applied electric field, viewing angle characteristics are not high.
To solve this problem, a fringe field switching mode LCD device having improved viewing angle characteristics has been introduced.
FIG. 1 is a plan view of one pixel region of an array substrate 41 for the related art fringe field switching mode LCD device.
Referring to FIG. 1, a plurality of gate lines 43 each having a straight-line shape extend in one direction, and a plurality of data lines 51 each having a straight-line shape cross the plurality of gate lines 43 to define a plurality of pixel regions P.
Each of the plurality of pixel regions P is connected to one of the plurality of data lines 51 and one of the plurality of gate lines 43, which define the pixel region P, and includes a TFT Tr which is a switching device including a gate electrode 45, a gate insulating film (not shown), a semiconductor layer (not shown), and source and drain electrodes 55 and 58.
Also, in each of the pixel regions P, a pixel electrode 60 that has a plate shape and that is electrically connected to the drain electrode 58 of the TFT Tr is formed.
Also, in an entire display region including the plurality of pixel regions P, a common electrodes 75 is formed to correspond to each of the plurality of pixel regions P, overlap with the pixel electrode 60 having the plate shape, and include a plurality of bar-type openings op that are formed in the corresponding pixel region P and long axes of which are arranged in a direction in which the plurality of data lines 51 are arranged. Although the common electrode 75 is formed in the entire display region, a portion of the common electrode 75 corresponding to one of the plurality of pixel regions P is denoted by a dotted line.
In the array substrate 41 for the related art fringe field switching mode LCD device having the structure described above, a fringe field is formed by applying voltage to the common electrode 75 having the plurality of bar-type openings op and the pixel electrode 60 in units of the plurality of pixel regions P.
However, since in a fringe field switching mode LCD device having the array substrate 41 described above, a single domain is formed in an entire display region, a color shift phenomenon occurs when an image is viewed in an upper right direction, an upper left direction, a lower right direction, and a lower left direction. That is, yellow is strongly presented when an image is viewed in the upper left direction, and blue is strongly presented when the image is viewed in a vertical direction, thereby degrading display quality.